I would like to know if there is a possibility to dynamically listen to all ivy standard processes starts and ivy task creations and starts.
The idea would be to get a reference to any standard processes-cases that are started or tasks that are created.

There is yet no public API for that available. But there is an internal workflow event API that could handle this job - and the classes are accessible. So you can use it, but there is no guarantee that this API will not be changed or broken in the future.

The following sample code shows how you can track newly created cases. Many other events are also available: see the class ch.ivyteam.ivy.workflow.WorkflowEventKind

The proces start event is not fired as this workflowEvent framework does only handle case/task changes on persistency level.
But a picked up case lifes only in the memory until a taskSwitch is reached. So no event is fired. You could may work around the problem by forcing a persistent state by a placing a dummy taskswitch after the start